Attack dpx install advice

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Tree killer

Member
Jan 10, 2015
6
Central Maine
I purchased an attack dpx 45 profi this past fall. I have looked at a lot of information on here about installing them but would like to get advice on what and what does not work. Currently I have a central owb running so time to install is not that important. I will be removing the owb and hooking the attack up to existing oil boiler. I plan to add storage after initial install is complete. House is 2600 sf colonial first floor radiant and upstairs baseboard and a 1600 sf garage with radiant. Any input on plumbing, valves and pumps that perform well, running dump zones, etc is appreciated. I am very familiar with conventional wood boilers, both indoor and out, but have never seen a gasser in action only read a lot on here.
 
AFAICT there's not much peculiar to the DPX 45 to worry about compared to all the other downdraft gassers. I think they specify a 65 degC (149 degF) minimum return temperature as opposed toe 60 degC (140 degF) that the others require, but in any event you need to make sure that with or without storage you have return temperature protection figured out.

Then there's overheat protection, dump zone vs. siphon to storage, which depends a lot on your install site. Also the Attack's have a cooling coil that I think could be used if you have a reliable flow of water with or without power.

Can you describe more about where the boiler is going and where storage is going?

And you may have noticed people often mention the need for dry wood.
 
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Boiler and storage will be in basement right beside existing oil boiler. Owb will be removed which currently is hooked to existing system. It does have a cooling coil, instructions say to hook to fresh water supply and dump to drain. Problem is I have no place to drain and if power goes out so does water. We have a genset but not on-demand, I need to physically start it.
 
As far as wood foes I cut it everyday. Have 10-15 cord in the shed at all times.
 
Check out the hydronic heat sticky that is at the top of the Boiler room forum for some good ideas as to where to start.

Can you draw a schematic of your current system? That will help with suggestions.
 
I have looked at the hydronic schematics above as well as many others. Have gotten lots of ideas. My current system is fairly basic. House was designed to heat with oil. 6 zones with 5 circulators. I have 2 zone valves for the first floor. Dhw via megastore indirect. Currently the owb circulates through oil boiler on a plate exchanger. If it's not economical or convenient to run wood in the off season I plan to run oil for dhw.
 
Boiler and storage will be in basement right beside existing oil boiler. Owb will be removed which currently is hooked to existing system. It does have a cooling coil, instructions say to hook to fresh water supply and dump to drain. Problem is I have no place to drain and if power goes out so does water. We have a genset but not on-demand, I need to physically start it.


My boiler also has a cooling coil but I didn't hook it up. It still has the same plastic caps on it that it was delivered with. Seems to be a Euro solution, relying on total-loss coolant flow. My overheat protection uses a normally open zone valve tied to an aquastat that will open at high setpoint & send water to my upstairs zones. Some will also circulate to storage. Both methods will also serve the same function in a power outage. For additional power outage protection I also have a UPS I use if it looks like the power might go out or I have to leave home with a good fire going. The higher you can get storage above your boiler, the better the convection flow will be to it - that will handle all the overheat in an optimum boiler/storage setup. Using a loading unit, vs. a Danfoss thermic valve & ordinary circulator, will I THINK also give better no-power flows. If your zone setup won't give a good arrangement for convection flow to existing zones, another good solution is to pipe up some baseboard sections in the ceiling above your boiler & tie that to the normally open zone valve.
 
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I have looked at the hydronic schematics above as well as many others. Have gotten lots of ideas. My current system is fairly basic. House was designed to heat with oil. 6 zones with 5 circulators. I have 2 zone valves for the first floor. Dhw via megastore indirect. Currently the owb circulates through oil boiler on a plate exchanger. If it's not economical or convenient to run wood in the off season I plan to run oil for dhw.

Well then you can probably tie your boiler in right at the flat plate point and just add a few controls to handle the swap over to oil. Lots of times that can be as simple as an aquastat on the supply line or your storage tanks.

I recommend a loading valve for return water protection just because its an easy solution. If you want to play with it, you can use pumping for protection instead.
 
As far as wood foes I cut it everyday. Have 10-15 cord in the shed at all times.

I don't think it's been mentioned yet but cutting wood every day is good but you need to let it season for a good 2 seasons before you use it in a downdrafter. The days of cutting today, burning tomorrow will be long gone with your Attack.

I created a thread quite some time ago illustrating my install of an EKO 40. It might be of some interest to you:

https://www.hearth.com/talk/threads/one-mans-eko-40-illustrated-story-start-to-finish.29042/
 
Few if any here use that cooling coil and instead use inverter power, normally open zone valves to a particular zone or a coil of fin tube hung above the boiler.
 
Steel6043 I normally clear about a dozen house lots a year plus do tons of storm damage and dangerous tree removal. My wood is rotated through the shed working from both ends. It's in there at least 1 1-2 years. That's always been for a wood stove we have. The owb is a different story though.
Fred61 my garage was a thought for a dump zone. Radiant slab can pull a lot of heat out. Any recommendation on that? I have been looking at variable flow loading valves but don't have any experience with them or inverter setups.
 
A 'proper' dump zone should have the ability to flow by convection - say when power goes out & pumps won't run. A slab won't do that.

EDIT: Also, you may be able to use the cooling coil as a tankless water heater coil - set up a recycling flow to your hot water tank & heat the DHW that way.
 
lso, you may be able to use the cooling coil as a tankless water heater coil - set up a recycling flow to your hot water tank & heat the DHW that way.
The install sheet says the 'aftercooling circuit' must not be used for any other purpose. (But I used mine as mounting posts for the control box, does that count?)

A 'proper' dump zone should have the ability to flow by convection - say when power goes out & pumps won't run. A slab won't do that.
As I like to point out, the Fukushima systems relied on pumps and fail-safe power supplies, not gravity.

Since the boiler in this case is going in the basement it sounds like all three best choices are available: dump to one or more of the house zones, dump to finned tube array above boiler, or dump to elevated storage. Since it sounds like storage installation might be delayed a season or two then maybe one of the first two options would be best in order to have it done once and for all.
 
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The install sheet says the 'aftercooling circuit' must not be used for any other purpose. (But I used mine as mounting posts for the control box, does that count?)

Yes, I should have bolded the MAY in my reply. I had a conversation about this with my dealer when I got mine - I'll just say the end conclusion to the conversation was 'inconclusive', although that was a while ago & my memory is a bit fuzzy. I would likely tend to go by what the boiler manual/install sheet says about it, for the being able to sleep at night factor.
 
Agree with the others here, the KISS principle makes the most sense when it comes to an overheat loop. You can have another circ to the slab, and then also an inverter, but now thats two expensive things that can both fail when you need them most.
 
I don't think it's been mentioned yet but cutting wood every day is good but you need to let it season for a good 2 seasons before you use it in a downdrafter. The days of cutting today, burning tomorrow will be long gone with your Attack.

I created a thread quite some time ago illustrating my install of an EKO 40. It might be of some interest to you:

https://www.hearth.com/talk/threads/one-mans-eko-40-illustrated-story-start-to-finish.29042/

Is it wrong that I think the cub cadet pulling the EKO is freaking cute?
 
Is it wrong that I think the cub cadet pulling the EKO is freaking cute?

That poor tractor. I've put her through her paces. I drool when I see some of the real man-tractors folks on this site own.
 
Tree Killer, where are you in Central Maine? I live in Easton, ME. I've got an Attack DPX 45 that I just fired up for the first time last week. tied in with my oil boiler and a 1000 gal storage tank that I built myself. I have 3 zones, 2 radiant heat and another baseboard, will be 3 radiant when we finish an addition. Everything is set up to run pretty much automatic, all I have to do is start a fire. If it goes out, the heat will pull from the storage tank and if that runs out of heat, the oil will kick on. I used a danfoss thermostatic mixing valve to keep return temps at the required 65C while also having a 15gpm flow rate. I sure studied this forum a lot and learned a lot putting this system together. You're welcome to come check it out sometime if you'd like. Send me a PM
 
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